1. Field of the Invention
The present invention relates to power supply systems. In particular, the present invention relates to a power management system for personal computers that provides power to the computer system in response to interrupts from external devices.
2. Description of Related Art
Conventional present day computer systems include a power supply that provides the power required to operate the computer system. The power supply is coupled to an AC voltage source and converts the AC voltage to a DC voltage. Typically, the power supply is coupled through a switch that is manually activated by the user and only provides power when the switch is closed. Since the switch is manual, it cannot be electronically activated to open and close to turn the computer off and on, respectively. Thus, the prior art does not provide a method for using external device interrupts or other electronic signals to control the application of power to the computer.
The prior art has attempted to reduce this shortcoming by keeping computers in the on or operational state continuously. However, such a practice wastes significant amounts of power. This practice also reduces the life of the electronic components that comprise computers. Additionally, with the advent of portable computers that have a very limited power supply, such continuous operation is not possible.
Therefore, there is a need for a system for providing power to a computer system in response to external events.
Another problem associated with power management systems of the prior art is the requirement of manually exiting all applications or programs being run on the computer before turning off the power. With most all personal computers, the user must exit the program before turning the power off, otherwise, the data used by the program will be destroyed or corrupted. Additionally, turning off the power without exiting the program even affects the operation of some programs. Thus, there is a need for a system that saves the state of the hardware and memory before turning off the power.